Hardness preserving reductions via cuckoo hashing

Itay Berman, Iftach Haitner, Ilan Komargodski, Moni Naor

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

A common method for increasing the usability and uplifting the security of pseudorandom function families (PRFs) is to "hash" the inputs into a smaller domain before applying the PRF. This approach, known as "Levin's trick", is used to achieve "PRF domain extension" (using a short,e.g,fixed, input length PRF to get a variable-length PRF), and more recently to transform non-adaptive PRFs to adaptive ones. Such reductions, however, are vulnerable to a "birthday attack": after queries to the resulting PRF, where being the hash function range, a collision (i.e., two distinct inputs have the same hash value) happens with high probability. As a consequence, the resulting PRF is insecure against an attacker making this number of queries. In this work we show how to go beyond the birthday attack barrier, by replacing the above simple hashing approach with a variant of cuckoo hashing - a hashing paradigm typically used for resolving hash collisions in a table, by using two hash functions and two tables, and cleverly assigning each element into one of the two tables. We use this approach to obtain: (i) A domain extension method that requires just two calls to the original PRF, can withstand as many queries as the original domain size and has a distinguishing probability that is exponentially small in the non cryptographic work. (ii) A security-preserving reduction from non-adaptive to adaptive PRFs.

Original languageEnglish
Title of host publicationTheory of Cryptography - 10th Theory of Cryptography Conference, TCC 2013, Proceedings
Pages40-59
Number of pages20
DOIs
StatePublished - 2013
Event10th Theory of Cryptography Conference, TCC 2013 - Tokyo, Japan
Duration: 3 Mar 20136 Mar 2013

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume7785 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference10th Theory of Cryptography Conference, TCC 2013
Country/TerritoryJapan
CityTokyo
Period3/03/136/03/13

Fingerprint

Dive into the research topics of 'Hardness preserving reductions via cuckoo hashing'. Together they form a unique fingerprint.

Cite this